Alaska Extended Forecast Discussion National Weather Service College Park MD 529 PM EDT Sat Jul 26 2025 Valid 12Z Wed 30 Jul 2025 - 12Z Sun 03 Aug 2025 ...Overview... Most of mainland Alaska through the upcoming medium-range period next week still primarily appears to be sandwiched between a nearly stationary mean closed low over the Gulf of Alaska and a shortwave trough moving through northern mainland and lifting into the Arctic Ocean. Meanwhile, the upper ridge initially crossing the Aleutians into the Bering Sea is forecast to de-amplify with time as the next series of well organized surface low pressure systems should be sliding east into the Aleutians toward the end of next week. ...Guidance Evaluation/Preferences... Latest guidance remains well-clustered with the Gulf of Alaska low being nearly stationary or moves ever so slightly toward the southern coastline by the end of next week. Meanwhile, model guidance shows a good signal for the next significant cyclone and frontal system to reach the Aleutians and Bering Sea later next week and onward. Elsewhere, there remains noticeable spread in the deterministic guidance to the north of Alaska regarding the potential amplification of a frontal wave. However, ensemble means indicate a stationary front may remain draping across the northern Alaskan mainland. This has dependncy on lingering uncertainty with the extent of upper ridge re-building later period over the mainland. Overall, the WPC Alaska medium range forecast suite was primarily derived from a composite of best clustered guidance from the 12 UTC ECMWF/Canadian and GEFS/ECMWF/Canadian ensemnble means. This approach maintains best continuity from the previous forecast. ...Weather/Hazards Highlights... It generally remains the case that much of the precipitation across mainland Alaska for next week will likely be associated with a main shortwave trough moving across northern Alaska where moderate rainfall can be expected along the Brooks Range through at least midweek. Occasional moderate rainfall can also be expected along the Alaska Range and southern tier of the state on the outer edge of the slow- moving cyclone in the Gulf of Alaska. While these rains may persist for a while, they are not expected to be heavy. Some wet snow may mix in at the highest elevations. Only occasional light rain is expected for portions of the southern coastline into the Panhandle. Onward fom next midweek, rounds of more appreciable rainfall is forecast to gradually overspread the Aleutians through the medium- range period. The associated low pressure systems/main low is forecast to move into the Bering Sea and also offer triple point low translation slowly east along the Aleutians, eventually working into blocky flow into the western Gulf of Alaska into next weekend. This should act to gradually spread associated organized rains into the western mainsland and into the Alaska Peninsula. Daily high temperatures are expected to remain below normal Tuesday and Wednesday across much of mainland Alaska with the passage of the shortwave trough along with clouds and rainfall. A state-wide warming trend is then forecast late next week. Elsewhere, warmer than normal conditions are expected to prevail across the Panhandle, the Northwest, and Southwest. The Aleutians will also be warmer than normal prior to the arrival of a front potentially next week. Schichtel Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html